In article ,
Richard Clark wrote:

maybe just similar to what is known as a
"nest of dipoles" that scanner enthusiasts have. They use different
radiating elements in parallel.

Hi Jason,

Not that at all, otherwise all of the elements would be driven, and
simple observation negates that. I've reported a similar design to
this group years ago that uses the SO-239 bulkhead connector wired up
in similar fashion: One wire extending directly from the center pin
solder tail, and another wire, parallel, soldered to any of the four
holes normally used for mounting. No need whatever for the usual
JPole tuning cap.

There's an analysis of a similar design on Cebik's web site - his
"non-standard J-pole" is a bottom-fed, non-shorted design with a
shorter-than-usual radiating section and a longer-than-usual matching
leg.

http://www.cebik.com/jp1.html

It looks to me as if the Arrow design has similar element lengths to
the one which Cebik models. The Arrow trick of using one element as
the matching leg for 2-meter and as the radiator for 440 is a slick
one.

Everyone I've spoken with who has used an Arrow 146/440 J-pole has
been very happy with it.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

On Thu, 17 Jun 2004 22:22:22 -0000, (Dave Platt)
wrote:

Hi Jason,

Not that at all, otherwise all of the elements would be driven, and
simple observation negates that. I've reported a similar design to
this group years ago that uses the SO-239 bulkhead connector wired up
in similar fashion: One wire extending directly from the center pin
solder tail, and another wire, parallel, soldered to any of the four
holes normally used for mounting. No need whatever for the usual
JPole tuning cap.

There's an analysis of a similar design on Cebik's web site - his
"non-standard J-pole" is a bottom-fed, non-shorted design with a
shorter-than-usual radiating section and a longer-than-usual matching
leg.

http://www.cebik.com/jp1.html


Hi Jason, Dave,

A repeat of a subset of data offered here 5 and 7 years ago from data
measured at the bench 12 years ago:

.... built up from 0.085" diameter bronze tubing. In each case, the
center connection is brought out 13 inches.... with one vertical
element that paralleled the main element with a constant separation of
0.5 inch.

The variation of the second rod is called "Match Length" in the chart

Radiator Match Fo SWR
Length Length MHz 50 Ohm

13.0 6.0 485 2.8
13.0 5.75 548 2.3
13.0 5.5 556 1.8
13.0 5.25 576 1.8 (545-630 3:1)
13.0 5.0 624.5 1.48 (575-640 2:1)
13.0 4.75 638 1.08 (640-660 2:1)

73's
Richard Clark, KB7QHC

can you build a copper pipe beam ant

Subject: To those that said it would not work
From:
Date: 17, Thursday June, 2004 11:34 PM
Message-id:

can you build a copper pipe beam ant

Why would I want to ?

73 Al Lowe N0IMW
ArrowAntenna.com

why you a cry baby .